Wolf , that would work !!! That deck paint looks cool , but pricy , but if it actually lasts that long , then it's probably worth it... even if it lasted half that , still longer than me ....
Eagle , all done now ... covering was pretty EASY ... thinking on a large build , a couple extra hands wouldn't hurt , Clean hands that is ... The material on the roof overlapping the sides , went on well without any puckering on the curves..
I'd think a 2" or 3" overlap would be No problem on a large build , more around the floor , it's straight and very easy... It's drying now as the camera batteries charge ... I just laid down the glue , stretched the canvas over the foam and smoothed it out ... wasn't planning on a top coat of glue ... not really necessary as the paint will cover all ... and soak in the canvas better ... You could do anything you want with it finish wise , clear , paint , artwork , whatever.. a primer over the canvas would give a smoother surface ... I'm not worried about that ...
I'd just think of, and treat this as one would with a fiberglass trailer ... same thing basically ... and no reason why fiberglass could be used on this ... So a hatch could be lightly framed and covered ... not much stress on a light hatch ... Board inset for the hinges on each side ... For me , The Sleeper would be stronger as one piece , without the galley hatch ... besides at my age , I'm more of a "grazer" than a cooker .. Natural diet , fruit , berries , nuts, vegs ... All I have to do is make coffee...
And I can cook legumes in my solar cooker if I want to splurge ... and it's sunny ...
My latest solar cooker is a windshield reflector/protector and a large glass jar ... Elementary ... easily stowed... I can easily make tea or coffee solar too , just impatient for coffee in the morning ...